Multiple Pigmented Seborrheic Keratosis with Sebaceous Differentiation - A Case Report.

Seborrheic keratosis is a benign lesion that is common in the trunk and head and neck regions. It shows a considerable variety of histological appearances leading to different variants. The presence of sebaceous differentiation in seborrheic keratosis is very rare and can histologically mimic benign and malignant tumors with sebaceous differentiation. We present a case of a 65-year-old male presenting with multiple nodules over the right and left sides of neck and the right preauricular region, histopathological examination of which revealed multiple pigmented seborrheic keratoses with sebaceous differentiation. This case is reported for its rare sebaceous differentiation and multiplicity along with the importance of differentiating it from a variety of benign to malignant neoplasms showing sebaceous differentiation.